Telephone trunk circuits



impart motion to the sprocket-wheels 38 on the corresponding ends of theshafts 26 of the sandpapering drums through the medium of link chainbelts 64;, 64. Shaft 58 is driven by the motor through the medium ofsprocketwheel 14, and a chain belt 56, which latter engages asprocketwheel 61, mounted and secured on said shaft 58 between gears and62.

This belt 56 also passes around and drives a sprocket-wheel 59, mountedupon and se cured to a transverse shaft 60, in line with the gear (it onshaft 58 and this shaft 60 extends through suitable openings or bearingsin the shield and apron and extends through and is journaled in bearingsin the drop-rranies 2- and 3 and constitutes the drive-shaft through themedium of wnieh the supporting-frame propelled. In order to perform thisfunction it passes transversely through a suitable housing and withinthis housing has a worm 72 securely mounted thereon that engages aworm-gear T1 on the adjacent end of a short longitudinal transmissionshaft 70, which latter is journaled in the ends of the housing 67 and ina partition, 68, that separates the chamber in which the worm andworm-gear mesh from the remainder of the interior of the housingconstituting a chamber 69. lVithin chamber 65),- transmission-shatt '70has a pair of connected or twin gears '75 securely mounted thereon, andone of the twins is in constant mesh with an idle-gear 76 lie ed to anidle-shaft 77 whose ends are journaled in partition 68, and in the endof the housing constituting the opposite wall of chamber 69. Idle-shaft'77 has another idle-gear T8 securely mounted thereon near the partition 68 that, preferably, corresponds in construction and dimensions toidle-gear '78. and this latter gear is adapted to be engaged by a gear79 that is splined to and is adapted to reciprocate on a longitudinaldrivenshaft 78. When reciprocated to the limit of its movement towardthe partition gear 79 engages the idle-gear 78. and is driven andimparts motion to shaft in one direction, and when reciproeated to thelimit of its movement in the opposite direction, it engages the nearestof the twin gears 75, and is driven and imparts motion to shaft 73 inthe opposite direction, Shaft 73, is extended through its bearings inthe end wall of housing 67 to and enters the centrally situatedenlargen'ient of the tubular casing T42, where its end has a bevelledgear,secured thereon that meshes with a bevelled gear-mounted on theaxleof the drive-wheels 5, 5.

The sliding gear 79 is formed with an elongated hub 80, equipped with acircunn ferential groove 81, to receive prongs 82 o'l a block 88,slidable on a rod 84 which latter extends parallel to the driven shaft'70 and slides in bearings provided in one end wall oil: the gear casing67 and in the intermediate wall 68. Block 88 is pivotally connected by alink 85 to the lower end 86 a hand lever 87, pivotally secured at 88,and i adapted to shift the block 83 into one of three positions, asindicated in dotted and full lines in Figure 8. The lever 87 is providedwith a spring-controlled pawl 97 adapted to enter notches in a quadrant98 secured to the platform 1.

Referring to Figure 8 it will be seen that in the extreme left positionshown in dotted lines, the slidable gear '79 meshes directly with thegears 75 while in the extreme right position the gear '79 engages therear wheel '78, so as to receive rotation from the driven shaft by theagency ot the idler gear 76.

A vertical steering-post 89 is secured to toe center or" length ot thefront axle 6, and its upper end has a horizontal arm 40, projectingtherefrom whici, at its tree end, is tormed with a boss 91 in which aspindle 02 has bearings. This spindle has at its upper end, a hand-wheel93, and at its lower end has keyed thereto a pinion 94!: that mesheswith a toothed quadrant 95 secured to a standard 96 secured to andarising trom the platform. 1.

Upon manipulation of the hand-wheels 93, the pinion 94: is rotated and,being in mesh with the quadrant 95 the arm 90, is es cillated and thesteering post 89 is rotated to impart steering movement to the frontaxle 6.

For the purpose of removing loosened dirt, shavings and dust from thesurface being operated upon, pipes 99 and 100 terminate adjacent to theinner side of each of the abrading drums 2T,tne ower ends of the pipesbeing 0 'panded late elled to facilitate the entrance o Pipes 99 andlilo are conneoed 101 and 102 to common riser which latter leads to theinlet opening of the fan 10 and is discharged through the exhaust 1041.

The operation of the machine t,-,ou.ght to be obvious "from theforegoing description.

The connection ot the motor 1? to source of electric power is controlledby an electric switch generally design; h 05. Upon closing the switchthe motor is mtuate and thereby the drums 27, the tan i and thedrive-shaft 60 are simultaneouslv tated. The operator stands upon thepiatform 1 and foot pressure is applied to the h aded-pin or trcadlc 51,to depress the drums 27 and press the same downwards to obtain thedesired functional contact with the surface to be smoothed.

1. 16 drive to the rear wheels will propel the entire machine so thatevery part of the surface iv he reached; the steering means enablingconvenient travel in any direction. (to reverse (a xp up 7" o pal.

GEORGE KUHN AND ERIC B. LUNDIUS, OF BROOKLYN, NEW YORK, ASSIGNORS T0AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A. CORPORATION OF NEW YORK.

TELEPHONE TRUNK CIRCUITS.

Application filed April 10, 1918.

To all to 710m it'may concern:

Be it known that we, Gnonon W. KUHN and Time R. LUNoiUs, residing atBrooklyn, in the county of Kings and State of New York, respectively,have invented certain Improvements in Telephone Trunk Circuits, of whichthe "following is a specification.

This invention relates to telephone systems and particularly talkingcircuits such as those between operators at difierent central ofiices ina system 0t associated exchanges.

The invention is here illustrated in a circuit designed to connect acentral test desk with the frame men or other operatives in any one of anumber of exchanges. While it is especially suitable for this purpose itis obviously applicable wherever similar conditions obtain. In a circuitof the kind mentioned the test man at the central desk is provided witha standard operators telephone set. At the other end of the line,however, there may be a number of telephones connected in multiple anddistributed along the main frame or elsewhere and for these it isdesirable to use the staniilard central battery subscribers set. Localbattery sets would require special attention For their maintenance andare otherwise less convenient for the purpose. ()n the other hand, .ifcentral battery sets are used. special arrangement must be made toprovide the talking current because circuits of the kind mentioned aboveare not associated with 4 cord circuits carrying the usual equipment forcommon battery supply, and because the distances ot the variousexchanges from the central test desk will frequently be too great foreiiicient energization from the central battery there located. v

It is the object ot the present invention to produce an improved circuitfor sevice of the character above indicated; to provide for energizingthe central battery sets from the battery supply local to the exchangeswhere the respective sets are used. to arrange the ringing circuits fora plurality oi sets at this character so that they may be rungselectively and so that the ringing and talking circuits will notinterfere one with the other. and to provide at the same time for thesignaling of the central test desk form the various local stations.

The invention will be more fully under- Serial No. 227,687.

stoodby reference to the acconiipanying drawing, in which the singlefigure represents diagrammatically a circuit embodying the invention.

One position of a central test desk is indicated generally on thedrawing at 1 and one of a number of telephone sets located at anassociated exchange is represented at 2 with line conductors 3 and 4extending between the exchanges. At the test desk is a key 5 of knownform with talking and holding positions 6 and 7 respectively. When thekey is thrown to position 6 the line is connected to the operatorstelephone set not shown and when thrown to the position 7 the line isheld while the telephone set is disconnected therefrom. Telephone set 2at the other station is a standard common battery subscribers set, theform illustrated being well-known and needing no further description.The terminals 8 and 9 0t this set are normally disconnected from theline conductors 3 and 4t but are associated with switch contacts 10 and11 whereby connection to the line may be made when desired. Thesignaling device 12 is normally connected to the line conductor 3through the switch contact 13 and on the other side to ground throughthe condenser and switch. contact 14;.

The switches for connecting the telephone set and the signaling devicewith the line are all under the control of? the relay magnet 1.5, whosewindings are of low resistance and are permanently connected across theterminals of the telephone set. Two windings are preferably used inorder that they may serve the additional purpose of retardation coilsfor the battery supply, the battery 16 for supplying the talking currentbeing connected between the two windings of the relay 15 as shown on thedrawing. I The leads 17, 18 and 19 represent multiple connectionsrunning to other telephones of the same character and with the samesystem of connections as just described. There may be any convenientnumber of such telephones located at suitable points, according to theservice to be rendered.

At the central test desk end of the line are suitable relays 20. 21 and22 for control ling the signaling at that end of the line. The relay 20has two windings normally connected in series across the conductors 3telephone set, means for connecting the telephone terminals to lineconductors upon removal of the telephone receiver from the hook, asignal device associated with the line line conductors In testnnony wmeans responsive to across said hereof, I have signed my name to thisspecification this first day of April, 1918.

GEORGE W. KUHN. In testimony whereof, I have signed my name to thisspecification this 8th day of April, 1918.

ERIC It. LUNDIUS.

